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            <p class="top-buffer">
              The Gravity Recovery Object Oriented Programming System (GROOPS) is a software toolkit written in
              C++ that enables the user to perform core geodetic tasks. Key features of the software include gravity
              field recovery from satellite and terrestrial data, the determination of satellite orbits from global
              navigation satellite system (GNSS) measurements, and the processing of GNSS constellations and ground station networks.
            </p>
            <p>
              Most tasks and algorithms are (optionally) parallelized through the Message Passing Interface (MPI), thus the software enables a
              smooth transition from single-CPU desktop computers to large distributed computing environments for resource intensive tasks.
            </p>
            <p>
              For an easy and intuitive setup of complex workflows GROOPS contains a graphical user interface where configuration files can be created and edited.
            </p>

            <p>
              <ul>
                <li><a href="#citing-groops">Citing GROOPS</a></li>
                <li><a href="#installation">Installation</a></li>
                <li><a href="#getting-started">Getting Started</a></li>
                <li><a href="#releases-and-contributing">Releases and Contributing</a></li>
                <li><a href="#license">License</a></li>
                <li><a href="#contributors">Contributors</a></li>
              </ul>
            </p>

            <h2 id="citing-groops">Citing GROOPS</h2>

            <p>If you use data sets computed with GROOPS in a publication or publish the data itself, please cite our reference paper.
              A <a href="https://doi.org/10.1002/essoar.10505041.1">preprint</a> is available on the ESSOAr, which can be cited as:</p>
            <p>
            <i>Mayer-Gürr, T., Behzadpour, S., Eicker, A., Ellmer, M., Koch, B., Krauss, S., Pock, C., Rieser, D., Strasser, S., Suesser-Rechberger, B., Zehentner, N.,  Kvas, A. (2020).
              GROOPS: A software toolkit for gravity field recovery and GNSS processing. Earth and Space Science Open Archive.
              <a href="https://doi.org/10.1002/essoar.10505041.1">https://doi.org/10.1002/essoar.10505041.1</a></i>
            </p>
            <div  class="bg-light">
            <pre><code>@article{10.1002/essoar.10505041.1,
  author = {Mayer-Gürr, Torsten and Behzadpour, Saniya and Eicker, Annette and Ellmer, Matthias and Koch, Beate and
  Krauss, Sandro and Pock, Christian and Rieser, Daniel and Strasser, Sebastian and Suesser-Rechberger, Barbara and
  Zehentner, Norbert and Kvas, Andreas},
  title = {{GROOPS}: A software toolkit for gravity field recovery and {GNSS} processing},
  journal = {Earth and Space Science Open Archive},
  pages = {8},
  year = {2020},
  DOI = {10.1002/essoar.10505041.1}
}</code></pre>
            </div>

            <h2 id="installation">Installation</h2>

            <p>GROOPS is written in C++ and contains some legacy Fortran code. To enable an intuitive interaction
               with the software, GROOPS includes a graphical user interface (GUI). The GUI is also written in C++
               and depends on the Qt toolkit.</p>
            <p>A detailed installation guide for Microsoft Windows and various Linux distributions can be found on the
            <a href="https://github.com/groops-devs/groops/blob/main/INSTALL.md">Installation</a> page.</p>

            <h2 id="getting-started">Getting Started</h2>

            <p>After a successful installation our <a href="html/index.html">Documentation</a> is the perfect way to get
               familiar with the different features of GROOPS.</p>

            <p>GROOPS depends on data files such as Earth rotation, Love numbers, and wavelet coefficients.
               An initial data set that is regularly updated is available on <a href="https://ftp.tugraz.at/outgoing/ITSG/groops/">our FTP server</a>.
               You can choose between downloading the data directory or a single <a href="https://ftp.tugraz.at/outgoing/ITSG/groops/data.zip">zip file</a> with the same content.</p>

            <h2 id="releases-and-contributing">Releases and Contributing</h2>

            <p>If you encounter a bug, please let us know by <a href="https://github.com/groops-devs/groops/issues">filing an issue</a>.</p>
            <p>At the moment we do not plan to have a regular release cycle, rather we will release a new version when a new
               feature has become mature enough, or for critical bug fixes. GROOPS has functionality in place to handle
               interface changes, however we cannot guarantee backwards compatibility for all configuration files.</p>
            <p>We appreciate all contributions including documentation and examples for the cookbook. If you want to
               add new functionality to GROOPS, please open an issue and discuss the feature with us.</p>
            <p>Please see our <a href="https://github.com/groops-devs/groops/blob/main/CONTRIBUTING.md">Contributing</a>
               page to learn about how to best contribute to GROOPS.</p>

            <h2 id="license">License</h2>
            <p>GROOPS is licensed under GPLv3, as found in the <a href="https://github.com/groops-devs/groops/blob/main/LICENSE">LICENSE</a> file.
               This license applies to all files in the repository unless otherwise indicated.</p>

            <p>Information about external source code contained in the repository can be found in the
            <a href="https://github.com/groops-devs/groops/blob/main/source/external/README.md">corresponding README</a>.</p>

            <h2 id="contributors">Contributors</h2>
            <p>Parts of GROOPS originate from developments in the Astronomical, Physical and Mathematical Geodesy Group
              at the University of Bonn, Germany. Since 2010 it is developed and maintained at Graz University of Technology, Austria.</p>

            <p>Here is a list of current and past contributors:</p>

            <p><a href="https://github.com/tmayerguerr">Torsten Mayer-Guerr</a>, Annette Eicker, Daniel Rieser, Norbert Zehentner,
            Christian Pock, <a href="https://github.com/x49">Matthias Ellmer</a>, Beate Koch, <a href="https://github.com/akvas">Andreas Kvas</a>, Saniya Behzadpour,
            <a href="https://github.com/sestras">Sebastian Strasser</a>, Sandro Krauss, Barbara Suesser-Rechberger</p>
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